The invention relates to a dishwashing machine, particularly a household dishwashing machine, at least having a washing compartment for accommodating items to be cleaned which are able to be cleaned at least during a cleaning step by adding cleaning agent.
Reducing energy consumption in dishwashing machines, especially household dishwashing machines, is of great importance. A reduction in energy consumption can be achieved by the use of so-called low-temperature programs, for example in conjunction with suitable low-temperature cleaners in which liquid, i.e. water, to which cleaning agent has been added if necessary, is heated up to a maximum temperature of 50° C. for example. However the continuing use of these type of low-temperature programs results in fatty contaminant films being able to adhere to the interior of the washing compartment. To remove such fatty contaminant films a special machine cleaner can be used which however also requires a special cleaning cycle of an otherwise unloaded dishwashing machine, with operation at at least 65° C. being necessary in this case. As an alternative, instead of a low-temperature program for reducing fatty contaminant films, a normal or high-temperature program, in which liquid is heated up to a maximum temperature of around 65° C. or around 75° C. in an intensive program for example can be selected. In such cases the selection can be made by an operator manually or can be made automatically by the dishwashing machine itself. However, like operating an otherwise empty dishwashing machine, this increases the energy requirement.
One option for preventing soiling building up, especially in the door area of a dishwashing machine, before it can occur is proposed in US 2006/0096615 A1. In order to ensure that the said soiling is flushed out after each wash cycle, the circulation pump is stopped for a certain time after a cleaning section, so that the liquid level within the dishwashing machine rises to a specific level as a result of the flowback of washing liquor. Ultimately this flushes soiling into the area of an outlet and in this way it can be drained out of the dishwashing machine. The washing liquor is cooled off again however in the sections in which the circulation pump is at a standstill so that a renewed heating of said liquor has to be undertaken subsequently.